Biochar-mediated sorption of antibiotics in pig manure

A. N. Ngigi, Yong Sik Ok, S. Thiele-Bruhn

Research output: Contribution to journalArticlepeer-review

75 Citations (Scopus)


Using manure contaminated with antibiotics as fertilizer is a primary source of soil pollution with antibiotics and concomitantly with antibiotic resistance genes (ARG). Bioavailable antibiotics trigger further ARG amplification during manure storage. Consequently it is aimed to facilitate the immobilization of antibiotics in manure. To this end, five biochars derived from pine cone (BCP), rice husk, sewage sludge, digestate and Miscanthus were tested as additional sorbents in liquid pig manure for sulfamethazine, ciprofloxacin, oxytetracycline and florfenicol. Non-linear sorption was best-fit using the Freundlich isotherm (R2 > 0.82) and the pseudo-second-order model best described sorption kinetics (R2 > 0.94). Antibiotics’ sorption onto manure increased in the order sulfamethazine < florfenicol < ciprofloxacin < oxytetracycline. Admixtures of BCP to manure changed the order to sulfamethazine < oxytetracycline < florfenicol = ciprofloxacin. Generally, with the addition of biochar, sorption coefficients of florfenicol increased most (by factors>2.7) followed by sulfamethazine and ciprofloxacin. Yet, oxytetracycline was mostly mobilized probably due to competitive adsorption. Effects depended on the proportion of biochar added and the type of biochar, whereby plant-derived biochar exhibited better immobilization of antibiotics. Depending on the type and portion of biochar, admixtures to manure can be used to lower the mobility and hence bioavailability of fenicols, fluoroquinolones and sulfonamides.

Original languageEnglish
Pages (from-to)663-670
Number of pages8
JournalJournal of hazardous materials
Publication statusPublished - 2019 Feb 15

Bibliographical note

Funding Information:
A.N. Ngigi received funding through a Postdoctoral Fellowship from the German Academic Exchange Service (DAAD). Laboratory materials and equipment were provided by Department of Soil Science, Trier University, Trier, Germany. We thank C. Emmerling, University of Trier, for providing us with the Miscanthus biochar substrate. We are grateful to Mrs. K. Wetzel (Keyence, Neu-Isenburg, Germany) for supporting us with the digital microscope and taking the images and we thank Mr. D. Ondigo of United States International University-Kenya for acquiring the FTIR spectra.

Publisher Copyright:
© 2018 Elsevier B.V.


  • Antibiotics
  • Biochar
  • Competitive sorption
  • Pig slurry
  • Sorption kinetics

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis


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